A hernia is the formation of an opening in the abdominal wall typically accompanied with abdominal tissue and viscera which push through the opening in the abdominal wall. The abdominal wall has several relatively weak regions where hernias tend to occur with greatest frequency. These include: 1) the internal inguinal ring where an indirect hernia occurs, 2) Hesselbach's triangle where a direct hernia occurs, and 3) the femoral ring where a femoral hernia occurs. Each of these defects is considered an inguinal hernia.
A femoral hernia forms in the femoral ring in the iliopubic tract spanning the gap between the inguinal ligament and the pubic bone. This conforms to the space between the femoral vessels and the pubic bone beneath the inguinal ligament.
A direct hernia is the result of weakness of the transversalis fascia that forms the floor of the Hesselbach's triangle. The Hesselbach triangle is bordered by the conjoined tendon and edge of the rectus sheath medially, the inguinal ligament at the base, and the inferior epigastric artery laterally and superiorly. The functional lateral and superior border of the direct hernia is actually the edge of the transversus abdominis muscle.
An indirect inguinal hernia is situated adjacent the direct hernia; the two being separated by the inferior epigastric artery. Unlike the other two hernias, the indirect hernia is the result of a congenital flaw. A sac of peritoneum follows the testis in its descent through the inguinal ring and into the scrotum during development. Normally, the sac seals itself as it passes through the internal ring.
The treatment of an inguinal hernia frequently involves surgery in an effort to repair the defect. In most inguinal hernias, abdominal tissue has pushed through a defect in the abdominal wall. Normally, the abdominal tissue forms a sac lined by the peritoneum with viscera contained in the sac. Treatment requires that the contents of the sac be returned to their normal position in the abdomen and the defect in the abdominal wall surgically repaired by suturing the ruptured fascia at the site of the defect in an effort to close and restore the integrity of the abdominal wall.
Conventional procedures for hernia repair may provide only temporary relief. Typically, they involve stretching of the musculature and ligamentous tissue in order to close the defect. The tissues are sutured while in a stretched configuration which makes the abdominal wall further susceptible to a recurring hernia. Thus, surgical correction of a recurring hernia often results in further degeneration of the involved fascia, muscles, and ligaments.
In an effort to avoid recurring hernias and the resulting progressive deterioration, surgeons commonly use implantable mesh material to repair the defect. A sheet of surgical mesh material, usually polypropylene or Gore-rex.TM., is placed over the defect and sutured in place as determined by the surgeon. A single sheet of surgical mesh, generally 3.times.5 inches in size, may be used to cover all three inguinal defects. Although some hernias may be successfully treated in this manner, others result in failure and recurrence of the hernia.
Endoscopic surgery has been a major improvement in the field of orthopedics, gynecology and general surgery because surgical procedures can be performed in a less invasive manner than previously possible. The surgeon performing an endoscopic procedure will make two to three small incisions rather than one large incision. He then uses an endoscopic camera to view the interior anatomy of the patient. He directs surgical instruments through the incisions not occupied by the camera to the surgical site and performs the surgical procedure. The use of smaller incisions requires that less muscle tissue be cut than when a single large incision is required. Generally, endoscopic procedures significantly reduce the surgical trauma to the patient and consequently reduce the recovery time that the patient requires.
While endoscopic surgery has been quite successful in dealing with many problems, it has not been as successful in the treatment of inguinal hernias. Using the endoscopic pre-peritoneal approach, a single 3.times.5 inch sheet of mesh may be used to cover all three inguinal detects. A problem arising with the endoscopic or laparascopic approach has been the lack of a predictably effective method of attaching surgical mesh to the tissues proximate to the pubic bone, an area commonly the site of recurrent hernias. Generally, in open surgical procedures for inguinal hernias where surgical mesh has been used, the mesh has been sutured to Cooper's ligament which is attached to the pubic bone. Cooper's ligament is a very tough, fibrous ligament offering good retention of mesh properly sutured to it. Endoscopically, surgical mesh has generally been attached by use of endoscopic staples. Endoscopic staples, however, have not proven to be predictably effective to attach surgical mesh to Cooper's ligament, thereby resulting in recurrence of hernias in the area proximate the pubic bone.
To complete existing procedures using mesh for repairing inguinal hemas, the remaining margins of the surgical mesh have been generally attached to surrounding tissue by endoscopic stapling. This portion of the procedure in endoscopic hernia repair has not proven to be as great a problem because recurrence of a hernia predominately occurs in the region of the pubic bone.